DD15 Troubleshooting – Section 24.2 SPN 97/FMI 4

Section 24.2
SPN 97/FMI 4

SPN 97/FMI 4 indicates a Water-in-Fuel circuit short to ground.‪

Check as follows:‪

1. Check for multiple codes.
   1. If any EGR faults are active at the same time, repair the open circuit between pin 67 of the MCM 120-pin connector and pin 3 of the Water-in-Fuel Sensor. Refer to "24.2.1 Verify Repairs" .
   2. If only fault 97/4 is active, go to the next step.
2. Disconnect the Water-in-Fuel Sensor.
3. Disconnect the MCM 120-pin connector.
4. Measure the resistance between pin 1 of the Water-in-Fuel Sensor connector and ground.
   1. If resistance is less than 5 Ω, repair short between pin 1 and ground. Refer to "24.2.1 Verify Repairs" .
   2. If resistance is greater than 5 Ω, go to the next step.
5. Measure the resistance between pin 2 of the Water-in-Fuel Sensor harness connector and ground.
   1. If resistance is less than 5 Ω, repair the short circuit between pin 2 of the Water-in-Fuel Sensor harness connector and ground. Refer to "24.2.1 Verify Repairs" .
   2. If resistance is greater than 5 Ω, go to the next step.
6. Measure the resistance between pin 3 of the Water-in-Fuel Sensor harness connector and ground.
   1. If resistance is less than 5 Ω, repair the short circuit between pin 2 of the Water-in-Fuel Sensor harness connector and ground. Refer to "24.2.1 Verify Repairs" .
   2. If resistance is greater than 5 Ω, review the previous steps. If the results are the same, contact Detroit Diesel Customer Support Center (313-592-5800).

Section 24.2.1
Verify Repairs

Verify repairs as follows:‪

1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.

   ENGINE EXHAUST ‪
   To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.‪

4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel Customer Support Center at 313–592–5800.